Pen



FIG. 1 is a front elevational view thereof;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 left side elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines in the drawings, including those showing the clip, and the vertical lines and features on the transparent band around the top, are included for the purpose of illustrating environment and form no part of the claimed design.

The stippling shown on the grip and buttons of the pen barrel represents a surface texture. 

The ornamental design for a pen, as shown and described. 